Journal of King Saud University – Computer and Information Sciences (2014) 26, 29–45

King Saud University

Journal of King Saud University –

Computer and Information Scienceswww.ksu.edu.sa

www.sciencedirect.com

ORIGINAL ARTICLE

Learning technologies for people with disabilities

Mohsen Laabidi, Mohamed Jemni *, Leila Jemni Ben Ayed, Hejer Ben Brahim,

Amal Ben Jemaa

Research Laboratory of Technologies of Information and Communication & Electrical Engineering LaTICE, National HigherSchool of Engineering of Tunis, University of Tunis, 5, Av. Taha Hussein, B.P. 56, Bab Mnara 1008, Tunis, Tunisia

Available online 22 October 2013

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KEYWORDS

e-Learning;

Accessibility;

AccessForAll;

Adaptation;

MoodleAcc+

Corresponding author. Tel.

-mail addresses: Mohsen

ohamed_jemni2000@yahoo.f

. Jemni), Leila.jemni@fs

nbrahim.hejer@gmail.com

ail.com (A. Ben Jemaa).

er review under responsibilit

Production an

19-1578 ª 2013 King Saud U

tp://dx.doi.org/10.1016/j.jksu

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.laabidi@

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Abstract Nowadays learning technologies transformed educational systems with impressive pro-

gress of Information and Communication Technologies (ICT). Furthermore, when these technolo-

gies are available, affordable and accessible, they represent more than a transformation for people

with disabilities. They represent real opportunities with access to an inclusive education and help to

overcome the obstacles they met in classical educational systems. In this paper, we will cover basic

concepts of e-accessibility, universal design and assistive technologies, with a special focus on acces-

sible e-learning systems. Then, we will present recent research works conducted in our research Lab-

oratory LaTICE toward the development of an accessible online learning environment for persons

with disabilities from the design and specification step to the implementation. We will present, in

particular, the accessible version ‘‘MoodleAcc+’’ of the well known e-learning platform Moodle

as well as new elaborated generic models and a range of tools for authoring and evaluating acces-

sible educational content.ª 2013 King Saud University. Production and hosting by Elsevier B.V. All rights reserved.

1. Introduction

The world report on disability affirms that over one billion

people in the world live with some disabilities and there areabout 150 million school-aged children with disabilities. Manyof these children are excluded from educational opportunities

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utic.rnu.tn (M. Laabidi),

Mohamed.Jemni@fst.rnu.tn

(L. Jemni Ben Ayed),

Brahim), benjemaaamal@

Saud University.

g by Elsevier

. Production and hosting by Elsev

0.005

and do not complete primary education. At the same line, re-cent UNESCO Global report (UNESCO Global Report, 2013)

indicates that people with disabilities face a wide range of bar-riers, including access to information, education and a lack ofjob opportunities. However Information and Communication

Technologies (ICT) can be a powerful tool in supporting edu-cation and inclusion for persons with disabilities. Technologi-cal development can enable people with disabilities to improvetheir quality of life (Arrigo, 2005). The successful application

of such technologies can make classrooms more inclusive,physical environments more accessible, teaching and learningcontent and techniques more in tune with learners’ needs

(UNESCO Global Report, 2013).In fact, the continuous progress of ICT raised the need to

move toward improving the learning quality applied in educa-

tion and training systems by addressing new perspectives andopportunities. e-Learning emerges as the answer to fulfill thatneed (Ben Brahim et al., 2013) and vouches to attend the

ier B.V. All rights reserved.

30 M. Laabidi et al.

learning needs of the students in a personalized and inclusiveway. Actually, there is no shortage of optimism about the po-tential of e-Learning to reduce barriers to education and im-

prove the lives of individuals with disabilities (Klomp, 2004).Therefore, developing accessible online educational environ-ments appears as a principal solution to address this issue

and to remove the barriers that people with disabilities maymeet when they access these learning technologies. An appro-priate technology has to provide people with disabilities with

adaptive and personalized learning experiences that are tai-lored to their particular educational needs and personal char-acteristics. It should also improve their satisfaction, learningspeed and learning effectiveness.

In this paper, we propose a conceptual abstract view of anaccessible learning environment and we describe a new processallowing the translation of a conceptual model into a specific

code adapted to the user’s individual learning context. Thetranslation process corresponds to a personalization processwhich supports people with disabilities learning by accommo-

dating and adapting the learning process to their needs.In this context, many researchers developed specific tools

dealing with specific needs for people with disabilities (Seale

and Cooper, 2010; Jemni and Elghoul, 2007; Elghoul and Jem-ni 2009). However, these tools do not allow the user to adaptthe contents to other needs. In fact, when we want to update,we have to modify existing codes. The new codes can be vali-

dated only by tests which make it difficult to guarantee thesoundness of the result and the preservation of previous prop-erties. For these reasons, we should consider accessibility from

an early stage of the systems lifecycle by giving generic modelswhich could be considered as a reference for the followingsteps of development. By this way, any tool is an instance of

such a model and any modification could give an updated con-tent generated by this generic model as a new instance whichrefines the previous one.

This paper starts by introducing the scope of our work. Sec-tion 2 reviews the state of the art related to accessible e-Learn-ing with a special focus on e-accessibility and its relatedinitiatives. Then, in Section 3, we describe our approach cover-

ing the different steps carried out to build an accessible e-Learning environment starting from the abstract model andreaching the code generation and evaluation phase. We will

also underline the particularity of the accessibility evaluationprocess we conducted within the e-Learning environment. Thissection ends through presenting our accessible e-Learning

environment MoodleAcc+. The paper is concluded inSection 4.

2. Background

In this sectionwe give an overview of the need of accessibility forpeople with disabilities. We focus on web accessibility and assis-tive technologies which offer new designs and tools satisfying

the requirements of people with disabilities. Then we presentbasic concepts of accessible e-learning and its state of the art.

2.1. e-Accessibility

2.1.1. People with disabilities

Disabilities can be grouped according to the type of impair-ment; generally there are four groups (Kavcic, 2005):

� Mobility impairments (restricted movement or control of

arms, hands and fingers): refer to physical disabilities thataffect the ability to move, to manipulate objects, and tointeract with the physical world

� Visual impairments (blindness, partial sight and colorblindness): include the range from low vision to full blind-ness, where the user cannot use the visual display at all.Although people with visual impairments have the greatest

problem with information displayed on the screen (espe-cially graphics and pictorial information), the use of apointing device, which requires eye-hand coordination

(such a mouse), may also pose an issue for them.� Hearing impairments (deafness and hearing loss): have dif-ficulties detecting sounds or distinguishing auditory infor-

mation from the background noise. Deaf individualscannot receive any auditory information at all. Many ofthem communicate through the Sign Language that differssignificantly from the spoken language. Cognitive impair-

ments (including cognitive, language and learning disabili-ties like attention deficit disorder, dyslexia, dementia,etc.): there are a wide range of cognitive impairments,

including impairments of thinking, memory, language,learning and perception.

2.1.2. Assistive technologies

Assistive or enabling technology includes devices, tools, hard-ware, or software, which enable, partially, people with disabil-

ities to use the computer. It presents an alternative way toaccess the content on screen, command the computer or pro-cess data. Specific adjustment software or devices for manipu-

lating the computer include (Arrigo, 2005).

� Screen reading software (speaks displayed text and allows

simulating mouse actions with the keyboard),� Screen magnification software (for enlarging the content ofthe screen),� Braille display (for displaying Braille characters),

� Alternate input devices (e. g. Screen keyboard) and specialkeyboard (to make data entry easier),� Keyboard enhancements and accelerators (like StickKeys,

Mousekeys, repeatKeys, SlowKeys, BounceKeys, or Tog-gleKeys), mnemonics and shortcut keys,� Alternative pointing devices (e. g. Foot operated mice, head

mounted pointing device, or eye tracking systems),

These aiding technologies can be either devices or equipments(hardware) e.g. Braille, or software applications e.g. screen read-

ing software. However, these technologies do not seem sufficientfor providing full support to peoplewith disabilities.Web contentproviders should also participate in the inclusion process bymak-

ing arrangements that allow particularities of people with disabil-ities to be taken into account when creating web content. Severalefforts were conducted toward addressing this issue.

2.1.3. The Web Accessibility Initiative (WAI)

Being conscious of the constraints witnessed by people withdisabilities in everyday life especially with web based applica-

tions, the W3C carried out a key solution promoting peoplewith disabilities in accessing, using and interacting with theweb through the Web Accessibility Initiative (WAI).

Figure 1 IMS ACCMD Components.

Learning technologies for people with disabilities 31

The WAI develops strategies, guidelines, and resources tomake the web accessible to people with disabilities (W3CWeb Accessibility Initiative, 2013).

The WAI targets, among others, web content through WebContent Accessibility Guidelines (WCAG) (Web ContentAccessibility Guidelines, 2013), authoring tools through

Authoring Tools Accessibility Guidelines (ATAG) (AuthoringTools Accessibility Guidelines, 2013) and user agent throughUser Agent Accessibility Guidelines (UAAG) (User Agent

Accessibility Guidelines, 2013).In the WAI model, the WCAG is complemented by acces-

sibility guidelines for browsing and access technologies(UAAG) and for tools to support creation of Web content

(ATAG) (Sloan et al., 2006).These guidelines are mainly based on the following four

criteria:

� Perceivable – information and user interface componentsmust be presentable to users in ways they can perceive,

� Operable – user interface components and navigation mustbe operable,� Understandable – information and the operation of user

interface must be understandable,� Robust – content must be robust enough that it can beinterpreted reliably by a wide variety of user agents, includ-ing assistive technologies (Laabidi and Jemni, 2009).

The WAI was widely deployed in various web applicationareas aiming to include the left out user groups. In fact, this

inclusion became an acquired right for the people sufferingfrom disabilities in different countries. Since education is oneof the major concerns of ICT, applying WAI in this domain

is very promising.

2.2. Accessibility in e-learning

Involving accessibility in e-Learning aims to ensure that theopportunities offered by the e-Learning paradigm are guaran-

teed to everyone, including people with disabilities.Asserting that, Sampson and Zervas (2011) describe the is-

sue of accessibility in relation to technology-enhanced training

by ensuring that learners are not prevented from accessingtechnology-supported resources, services, and experiences ingeneral due to their disability.

Therefore, acknowledging accessibility in e-Learning is akey issue vouching to promote and ensure e-inclusion of stu-dents with disabilities. Furthermore, it bares the potential toeradicate barriers witnessed by students with disabilities in

accessing on-line digital resources.In the same scope, Perry (2004) sustains that making e-

Learning accessible ensures that resources can be used by all

learners regardless of environmental or technological con-straints, and allows individual learning styles and preferencesto be accommodated.

2.2.1. IMS Global Learning Consortium specifications

The IMS Global Learning Consortium developed variousspecifications and guidelines focused on adaptation or person-

alization of resources, interfaces and content to meet the needsof individuals (IMS Global Learning Consortium, 2001).Among these specifications, the IMS Access For All is

designed to define and describe resource accessibility. Its goal

is to provide a means whereby resources are matched to theindividual accessibility needs and preferences of a particularperson (IMS Global Learning Consortium, 2013).

The IMS Access For All specification enfolds two elements:IMS Accessibility Metadata Description (ACCMD) (IMSGlobal Learning Consortium (2013) handling the description

of the learning resource and IMS Accessible Learner Informa-tion Package (ACCLIP) (IMS Global Learning Consortium,2013) ensuring the description of learner’s preferences.

2.2.1.1. IMS accessibility metadata description. One side of thematch is the description of the learning resource. An importantaddition to the metadata standards is Accessibility Metadata.

Accessibility Metadata elements provide information aboutthe resource such as the senses needed to process the resource,the ability of content to transform in ways necessary for acces-

sibility and the availability of equivalent resources (Treviranusand Roberts, 2008).

Accessibility Metadata divides learning resources into two

categories: (1) Primary resources and (2) equivalent alterna-tives (Fig. 1)

(1) Primary resource refers to the original resource createdby the author. The metadata that is collected for theseresources is kept to a minimum to reduce the workloadon the author (Treviranus and Roberts, 2008).

Information collected includes the following:

� A statement about the flexibility of the presentationand control of the resource.

� A statement about the mode of access that indicates

whether vision, hearing, text literacy or touch isrequired to use the resource.

� A URL for any known equivalent alternative such

as a caption file for a video resource. Equivalentor alternative resources replace or supplement pri-mary resources to address an accessibility issue thata learner may have with the primary resource.

(2) Equivalent alternatives: equivalent or alternativeresources communicate the same learning objective or

lesson as the primary resource, but do so in anothermodality that is accessible to the learner.

Through accessibility metadata, resources that are accessi-ble or can be made accessible are easily identified and utilizedby educators, learners or the learning management system theyemploy (Treviranus and Roberts, 2008).

2.2.1.2. IMS Accessible Learner Information Package. Theother side of the match is learner needs and preferences.

Through ACCLIP, the learner can express preferences for

Figure 2 IMS ACCLIP components.

Figure 3 The IMS/ISO specifications.

32 M. Laabidi et al.

how the resource should be displayed, how the resource shouldbe controlled and what form of content should be delivered.These preferences can be applied to both the standard system

and available assistive technologies. An important approach ofthe ACCLIP specification is that it is not disability-centric.

Instead of assuming preferences based on stated disability,

theACCLIP specification assumes that any learnerwill have dif-ferent access preferences depending on any number of factors:their location, bandwidth, access device and subject of studyto name a few.Access ForAll is about individualization and cus-

tomization for the learner in a way that benefits all learners.ACCLIP is the corresponding specification or match to

accessibility metadata: a learner is able to specify accessibility

preferences like text alternatives to image content, and theappropriate resource that meets these preferences can be iden-tified by the corresponding accessibility metadata (Treviranus

and Roberts, 2008).Accessibility preferences are grouped into three categories:

those related to content, those related to the content displayand those related to the control of the content as illustrated

in the Fig. 2.

2.3. IMS/ISO specification

More recently, a new standard has emerged into the accessibilityscene: the ISO FDIS 24751 Accessibility standards (ISO/IEC24751 Information Technology, 2008). As the IMS Access for

All specification, the ISO specification is based on the learners’profiling and on the description of the didactical materialsthrough metadata (Mirri et al., 2009) as described in the Fig. 3.

The framework is divided into the following concepts, which,when used in conjunction, make possible the matching of digitaleducational resources with the needs of individual users:

� A statement of the needs and preferences of the individualuser, at the time and in the context they are in 2000 (AccessFor All personal needs and preferences profile – PNP):

(IMS Access For All Personal Needs and PreferencesDescription for Digital Delivery Information Model,2013). It defines three elements, as shown in Fig. 4, being:

– ‘‘Display’’: defines how the interface and content shouldbe presented to the learner. It covers speech synthesizers(e.g. screen readers), screen enhancement (e.g. screen

magnifiers), text highlighting, Braille settings, tactile dis-plays, visual alternatives to audio alerts, and contentstructure.

– ‘‘Control’’: defines alternative ways of controlling thetechnology. It covers accessibility enhancements for astandard keyboard, virtual keyboards, alternative key-

boards, mouse emulators, alternative pointing devices,voice recognition settings, and navigation throughcontent.

– ‘‘Content’’: defines content preferences, such as alterna-tives to visual content (e.g. audio descriptions), alterna-tives to text (e.g. graphics), alternatives to audio content

(e.g. captions), links to personal style sheets and requestsfor extra time (Perry, 2004).

– A statement of the relevant characteristics of a resourceto be matched to the PNP (Access For All digital reso-

urce description DRD) which assumes two categoriesof resources: original and adapted (Fig. 5). An originalresource is the initial or default resource. An adaptation

contains the same intellectual content as an original re-source but in a different form such as in a different sen-sory mode, or with more or less dense semantics

2009(The IMS Global Learning Consortium, 2013).

Through its Accessibility Project and the specifications it

provided, IMS added a major value to the people with disabil-ities’ integration in online education. Several works deployedthe Access For All specification such as the two tools ATutorand TILE.

ATutor includes a variety of features designed to ensurethat content is accessible to all potential users, including thosewith slow Internet connections, older Web browsers, and peo-

ple with disabilities using assistive technologies to access theWeb (ATutor learning management system, 2003). ATutoruses the TinyMCE HTML editor, which is accessible to a

broad range of browser and assistive technologies, and whichprompts content authors to produce accessible content. Manyof the accessibility features in ATutor are based on the WebContent Accessibility Guidelines developed by the W3C and

a consortium of groups around the world.The Inclusive Learning Exchange (TILE) is a learning ob-

ject repository service that responds to the individual needs

of the learner. It provides the authoring tools, repository archi-tecture, and preference schema needed to support this learner-centric transformation (The Inclusive Learning Exchange

(TILE), 2004). Based on ACCLIP, TILE allows the user tocustomize the presentation of content to suit his own needs.

As described above, all accessibility solutions are based on

WAI and the Access For All specifications. They deal with oneproblem at the time: content or presentation. Furthermore allthese solutions are ad hoc implemented and they do not takeinto consideration the technology evolution. In the next

Figure 4 AccPNP components.

Figure 5 AccDRD components.

Learning technologies for people with disabilities 33

section, we will present our approach to build an accessiblee-learning environment covering all its steps, starting from

the design to the implementation.

3. Our approach to build an accessible e-Learning environment

Most available e-learning systems for learners with disabilitiesare limited to deliver accessible learning contents. However,the learners with disabilities need the whole accessible TEL

environment and not only the accessible content. In fact, pro-viding accessible content in a non accessible learning environ-ment leads to a non accessible learning experience. In the

following, we present the main limits of the available systems.

- Some of these systems are limited in a particular environ-ment so the posterior applications cannot profit from the

valuable experiences gained through local use and conse-quently cannot be easily identified and adopted by largercommunities of educational practitioners and training

organizations (Sampson and Zervas, 2011).- Many of them are typically based on accessible learningcontent that is designed and only recognizes the specific

accessibility requirements of a particular user group(Sampson and Zervas, 2011).

- The e-learning environment may contain some non accessi-ble tools that prevent people with disabilities access to the

content even though this is in an accessible format.- Some systems may provide content during the learning pro-cess that does not meet the specific needs of each type of

disability.

- Some systems use accessible learning resource designed to

be accessible to everyone, but not optimal to every user.- Most systems lack the possibilities of personalization sincethey give the same contents to all students (Chorfi and

Jemni, 2003).

Our approach targets to address these issues and to ensurethese objectives:

- Remedy to the lack of environments, taking into accountthe design of accessible e-Learning applications.

- Lead the learner in specifying his needs and preferencesregarding the control as well as the presentation of thelearning content he wishes to exploit in the e-Learning

environment.- Ensure that the content embedded in the e-Learning envi-ronment is fully exploitable and usable by learners withdisabilities.

- Ensure full accessibility of the learning environment in itscontent, its content presentation as well as its control.

- Adapt learning environment to meet the needs of people

with disabilities by personalizing the training process forevery user.

- Assert the establishment of the accessible environment for

e-Learning by developing and embedding a platform acces-sibility evaluation tool.

In order to reach these objectives the proposed approachrelies on 3 phases namely design, implementation and evalua-tion as exposed in Fig. 6.

3.1. Design of accessible e-Learning systems

Good design is at the core of inclusive educational technology(Treviranus and Roberts, 2008). Based on this assumption,

accessible e-learning refers to design qualities that endeavorto make online learning available to anyone irrespective oftheir disability, and to ensure that the way it is implemented

does not create unnecessary barriers to him/her interactingwith a computer or connecting device (Cooper, 2006).

Therefore, accessibility has been recognized as a key design

consideration for technology-enhanced training systems ensur-ing e-inclusion of people with disabilities in the training pro-cess and consequently preventing risks of ‘‘digital exclusion’’(Sampson and Zervas, 2011).

Unlike existent systems, based on an ad hoc accessibilityimplementation, we are considering accessibility from an earlystage of the systems lifecycle. For this reason, adopting the

accessibility since the design phases could provide a rationalsolution to this problem. A generic model could give an ab-stract view of elaborated systems which could be used as a ref-

erence description corresponding to specific tools supportingany update.

We carried out this solution by establishing a conceptualbasis that will allow to integrate accessibility in e-Learning

systems.In order to achieve the above mentioned, this section will

cover different works conducted in our LaTICE Research

Laboratory (Research Laboratory in Technologies of Infor-mation and Communication and Electrical Engineering,2013) to address the design of accessible e-Learning systems.

34 M. Laabidi et al.

First, we start by presenting the formalism to model accessibil-ity described in (Laabidi and Jemni, 2009) called Profile BasedAccessible E-learning formalism (PBAE). Then, we describe

the extension of this formalism by a new UML meta-modelin order to model e-Learning accessibility specifications. Thismeta-model is called ACCUML. ACCUML is based on the

IMS Access For All and gives the designer the possibility torepresent the keys of accessible e-Learning systems: the presen-tation and the control.

The basic pillar of these works was the OMGModel DrivenArchitecture (MDA) which was deployed as it turns out to bemost relevant to address accessibility from an early stage in thesystems lifecycle.

MDA is an approach based on Model view Systems. MDAseparates business and application logic from underlying plat-form technology [http://www.omg.org/mda]. This approach

depends on the definition of:

(1) Specification model called Computational Independent

Model or CIM,(2) Conception model called Platform Independent Model

or PIM,

(3) An implementation model called Platform SpecificModel or PSM,

(4) A set of model transformations (Laabidi and Jemni,2010).

We intend to develop a meta-model for accessible e-learn-ing systems which could be used to generate a specific system

for specific needs. Every elaborated system corresponds to amodel and every model has to be assigned to the same meta-model and not to the other one. This generic meta-model

allows adaptation, modification, and flexibility considering dif-ferent contexts. Those are guaranteed when a semantic link isdefined between elaborated systems and the meta-model by the

use of a transformation language ATL (ATL, 2006). For that,we need an UML profile considering e-learning aspects com-bined with accessibility requirements.

3.1.1. The Profile Based Accessible E-learning formalism(PBAE)

This formalism aims to define a modeling language for devel-oping accessible e-Learning systems. The PBAE is mainly

based on the definition of UML profiles which supportscustomizing by personalizing UML models for particulardomains and platforms (Fuentes-Fernandez and Vallecillo-

Moreno, 2004).

Figure 6 The proposed environment.

The PBAE applies UML profiles in the three levels relativeto the MDA approach. This idea is illustrated in Fig. 7.

Fig. 7 describes the PBAE architecture which associates a

profile to each level of the MDA approach. It shows that thetransfer from one model to another or the refinement of thesame model is ensured by a set of transformation rules driven

by UML profiles.

3.1.2. The ACCUML meta-model

In the same scope, we have extended PBAE into a new UML

meta-model called ‘‘ACCUML’’ for the modeling of digitalaccessibility in e-learning systems. This extension was per-formed to establish the basic foundations for modeling acces-

sibility. Through the ACCUML meta-model, the UML basicmeta-models were enriched in order to support accessiblee-Learning systems design.

Fig. 8 shows the proposed meta-model in order to supportaccessible e-Learning application. The applied extension is gi-ven by adding two concepts: the concept of presentation ‘‘Dis-play’’ and the concept of control ‘‘Control’’. The presentation

and control concepts were chosen considering their particular-ities for each type of disability, unlike non-disabled userswhere the presentation and control are elements of comfort

(Figs. 9 and 10). The Use Case Meta-model commonly de-scribes the application specification requirements which willbe presented through use cases.

This work is concretized through the development of a newcomputer based software engineering called ArgoUMLacc+. Inprevious works conducted within LaTICE Research Labora-

tory (Hebiri et al., 2010; Laabidi and Jemni, 2010; Laabidiand Jemni, 2009), we performed an adaptation of the IMS Ac-cess For All accessibility elements, in order to assert a person-alized learning experience. We designed accessibility models

corresponding to every type of disability by means of theaccess For All specification in order to develop accessibilitymodels that are specific to each disability type. These models

were developed according to the learner’s individual

Figure 7 Architecture of PBAE.

Learning technologies for people with disabilities 35

preferences and needs in order to match learning content withlearner accessibility preferences.

Then, we integrate them within the Computer Aided

Software Engineering ArgoUML (Mirri, 2006). The resultis ArgoUMLAcc+ through which we can create PlatformsIndependent Accessibility Models (PIM). The accessibility

models (PIM) consist in the learner’s needs and preferencesstatement personalized to his disability type.

3.2. Implementation of an accessible e-Learning environment

Following the previous step, the integration of the obtainedmodels in the e-Learning systems is needed. This integration

requires some transformations depending on the chosene-Learning platform. This transformation relies on transforma-tion rules which transform the PIM in order to obtain PlatformsSpecific Models (PSM) (Figs. 11 and 12).

Figure 8 The ACCU

3.2.1. Models transformations

After the elaboration of a platform independent Model (PIM),

we generate its correspondent XMI model by transformation.This makes easier the transformation into PSM and also theintegration. The following figures show how display and con-

trol appear in the XMI code.

3.2.2. Extension of PHP meta-model

To take into account the PHP platform in the MDA approach,

we chose the meta-model according to standard PHP MOFpresented below. This meta-model defines the structure PHPapplications models. The objective of the development of the

meta-model was twofold. On one hand, it allows the transfor-mation of models into UML 2.0 component model and PHP.On the other hand, it facilitates the generation of the PHP

code. This meta-model is a demonstrator illustrating the feasi-bility of our approach.

ML Meta-model.

Figure 9 The IMS Accessforall Control Model.

36 M. Laabidi et al.

To model the inclusion of PHP mechanism, we introducethe concept of resource, which represents any file accessible

via a path (Fig. 13).

a. The meta class ‘‘Resource’’, which has a metadata attri-

bute called path.b. The meta class ‘‘Library.’’ This meta class inherits the

meta class ‘‘Resource’’.

3.2.3. MoodleAcc+

To exploit the accessibility models and ensure their effective

use to establish an accessible environment for e-Learning, weintegrate accessibility models in the open source e-Learning

platform Moodle. The result is the new e-Learning environ-ment MoodleAcc+ that we developed as an accessible version

of the platform Moodle.With the platform MoodleAcc+ we can use the built-in

accessibility models while matching the content with learner

preferences to get a personalized learning experience.MoodleAcc+ offers several services to the e-Learning

community:

� Learner Assistance Tool,� Author Assistance Tool,� Accessible Course Generation Tool,

� Platform Accessibility Evaluation Tool.

Figure 10 The IMS Accessforall Display Model.

Figure 11 The XMI Display class transformation.

Figure 12 The XMI Control class transformation.

Learning technologies for people with disabilities 37

3.2.3.1. Learner assistance tool. MoodleAcc+ gives to learners

the possibility to specify and edit his preferences through its

Learner Assistance Tool. This tool is based on the specificaccessibility models we developed and integrated in Moodle.Once the learner specifies his disability type, the relevant model

is generated allowing the learner to state his preferences in apersonalized way.

Fig. 14 represents a screenshot of the wizard appearingonce the learner expresses his will to create his accessibility

profile within MoodleAcc+. It allows the learner to specify hisdisability type.

Once the selection is done, the specific accessibility model is

generated leading the learner to specify his preferences concerningthe content, the display and the control as shown in Fig. 15.

Figure 13 The Extended PHP Meta-model.

38 M. Laabidi et al.

3.2.3.2. Accessible course generation tool. Based on these pref-

erences and available contents, our system generates a person-alized learning experience conforming to the learnerpreferences. For instance, a learner is studying a course on

the solar system containing a video of the solar system’sformation and evolution. A user without a PNP file or witha PNP file, but without expressed needs or preferences con-cerning audio or visual content, would receive the original vi-

deo as shown in Fig. 16.However, another user who has a hearing impairment may

require captions. In this case, it would be necessary for the ori-

ginal video to be supplemented by an adaptation. When thisuser requests to view the course on the Solar System contain-ing the video of the solar system formation and evolution, the

system recognizes that the user needs an alternative to theauditory components. It checks the video’s adaptations anddiscovers that an adaptation exists with a caption that matches

user requirements. The metadata for the caption file indicatesthat it is a partial adaptation and should be displayed with thevideo. The system displays the video with its supplementarycaptions as shown below in Fig. 17.

Another illustrative example involves a color blind studentwho requires a course on the neural system. The course is

initially presented in its original format including a color imageas in Fig. 18.

This user proceeds on creating his PNP file in which he

specifies his request asserting that the information will not betransmitted through color. Therefore, the color images willbe replaced by gray level images in the generated course. In

our example, the generated course is shown in the Fig. 19.

3.2.3.3. Author assistance tool. MoodleAcc+ gives the authors

the possibility to index the learning resources with accessibilitymeta-data as well as providing several alternatives through itsAuthor Assistance Tool.

Fig. 20 is a screenshot of the course creation wizardwhich gives an author willing to create a course thepossibility to index the learning resources with accessibilitymetadata.

Fig. 21 is a screenshot of the accessibility metadata corre-sponding to the AccDRD specification through which theauthor specifies if he is willing to give adaptations to the origi-

nal resource.The Fig. 22 is a screenshot of the adaptation accessibility

metadata. The author can specify adaptations to be provided

and index them with the relevant accessibility metadata.

Figure 14 screenshot of the Disability type selection wizard.

Figure 15 Screenshot of learner’s preferences edition.

Learning technologies for people with disabilities 39

3.3. Evaluation of accessibility in e-Learning environment

To assess the accessibility of an e-Learning environment, wedeveloped a system to evaluate the accessibility of the e-Learn-

ing platform.To evaluate the accessibility we investigate how the needs of

learners with disabilities are considered in the e-Learning envi-

ronment, in particular, the way the learner can exploit the con-tent as well as the way the learner can get the content. Theevaluation module is integrated and applied in MoodleAcc+.

3.3.1. Platform accessibility evaluation

Accessibility evaluation is based on tools which are softwareprograms or online services that decide if web content meets

accessibility guidelines. However, even though the webcontent might be accessible, it does not mean that it is

profitable and exploitable by people with disabilities. Yet

accessibility evaluation tools are restricted to web content.Therefore, the need is to focus on evaluating the learningcontent as well as the e-Learning environment embedding

and delivering this content.The platform accessibility evaluation targets the enhance-

ment of e-Learning platforms regarding their accessibility con-siderations. To evaluate the accessibility, we analyzed how the

environment addresses the needs of the learner in control anddisplay, otherwise:

- How the learner can use the content?- How the content is going to be represented?

The evaluation is based on a validation of the Schematrondocuments. The Shematron is an ISO standard consisting ina language for making assertions about the presence or ab-

Figure 16 Screenshot of the solar system course video without captions.

Figure 17 Screenshot of the solar system course video with caption.

40 M. Laabidi et al.

sence of patterns in XML documents 2006(ISO/IEC Schema-

tron, 2013). For each learning object (content), we evaluateits control and display using validation based on XML She-matron documents. For each disability type, we perform a

diagnosis of the platform by parsing the corresponding dis-play and control Schematron files testing if the learning re-

source (content) meets the user preferences in control and

display.To properly perform the evaluation we need to create in

advance, based on the accessibility specific models already

elaborated, the Schematron files containing the display, con-trol elements from the AccPNP specific model and the content

Figure 18 Screenshot of the neural system course with a colored image.

Figure 19 Screenshot of the neural system course with a level gray image.

Learning technologies for people with disabilities 41

elements from the AccDRD specific model. Therefore, theevaluation follows the following steps:

� Extraction from the Data Base of the accessibility metadatacorresponding to the learning resource required by thelearner.

� Creation of the corresponding XML files structuring theaccessibility metadata extracted from the DB.� Validation of the XML files with the Shematron files

already created based on the accessibility specific models.

Finally, a report is generated detailing the accessibility flawsin the e-Learning platform in an easy and readable format.

3.3.2. MoodleAcc+ platform accessibility evaluation tool

This tool enables authors and tutors to evaluate the accessi-bility of a course within the given learning environment.

Through selecting a course, an author or a tutor can beaware of the accessibility problems that exist in the coursewithin the given learning environment. Furthermore, this

Figure 20 Screenshot of the course creation wizard.

Figure 21 Screenshot of AccDRD Accessibility Metadata.

42 M. Laabidi et al.

tool offers a personalized evaluation since the targeted usercan choose from the beginning which disability type theevaluation to be performed concerns. Fig. 23 shows a screen-

shot where the tutor is selecting a course to evaluate its acces-sibility for Blind disability within MoodleAcc+ learningplatform.

The evaluation diagnosed accessibility flaws regarding con-

tent, display and control. The report is provided in a table for-mat whose last column concerns a message about thecorrection to be performed to remedy each flaw.

Fig. 24 shows the wizard through which the user can view theevaluation reports already performed and saved in the data base.

4. Conclusion

In this paper we proposed a new approach for the developmentof accessible e-Learning environments. It consists of three

phases: design, implementation and validation. The approachhas been applied over the e-Learning platform Moodle. We

Figure 22 Screenshot of the adaptation accessibility metadata.

Figure 23 Screenshot of the blind platform accessibility evaluation report.

Learning technologies for people with disabilities 43

presented the MoodleAcc+ as the accessible version of theMoodle platform as well as a debrief of the offered services

within MoodleAcc+. It is noteworthy that our work is not lim-ited only to people with disabilities but it includes also anyonedisabled by his/her context.

We expect that our contribution will empower the effortsdeployed toward full inclusion of people with disabilities.

The elaborated meta-model for accessible e-Learning systemshelps to make automatic the generation of an accessible con-tent, the conformance of the content to e-Learning and acces-

Figure 24 Screenshot of Platform accessibility evaluation report viewing.

44 M. Laabidi et al.

sible properties as well as the transformation into an imple-

mentation adapted to specific needs and specific contexts. Thismeta-model supports accessible e-Learning application byadding two concepts: the concept of presentation ‘‘Display’’and the concept of control ‘‘Control’’.

The presentation and control concepts were chosen takinginto account their particularities for each type of disability.Withthe introduction of this meta-model, we avoid in particular ad

hoc accessibility implementation since we are considering acces-sibility froman early stage of systems lifecycle and any generatedsystem preserves the properties specified in the corresponding

model and allows the preservation of these properties after anymodification.

As a perspective of this work, we propose in the future to

investigate the modeling transformation process from abstractmodels to specific models. In addition, we intend to extend theapplication of our approach to other e-Learning platformswith a special focus on mobile learning.

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